title: A mechanical microconnector system for restoration of tissue continuity and long-term drug application into the injured spinal cord.
abstract: Complete transection of the spinal cord leaves a gap of several mm which fills with fibrous scar tissue. Several approaches in rodent models have used tubes, foams, matrices or tissue implants to bridge this gap. Here, we describe a mechanical microconnector system (mMS) to re-adjust the retracted spinal cord stumps. The mMS is a multi-channel system of polymethylmethacrylate (PMMA), designed to fit into the spinal cord tissue gap after transection, with an outlet tubing system to apply negative pressure to the mMS thus sucking the spinal cord stumps into the honeycomb-structured holes. The stumps adhere to the microstructure of the mMS walls and remain in the mMS after removal of the vacuum. We show that the mMS preserves tissue integrity and allows axonal regrowth at 2, 5 and 19 weeks post lesion with no adverse tissue effects like in-bleeding or cyst formation. Preliminary assessment of locomotor function in the open field suggested beneficial effects of the mMS. Additional inner micro-channels enable local substance delivery into the lesion center via an attached osmotic minipump. We suggest that the mMS is a suitable device to adapt and stabilize the injured spinal cord after surgical resection of scar tissue (e.g., for chronic patients) or traumatic injuries with large tissue and bone damages.
authors.affiliation: Molecular Neurobiology Laboratory, Neurology, Heinrich Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany. Electronic address: Nicole.brazda@uni-duesseldorf.de.
authors.forename: Nicole
authors.initials: N
authors.lastname: Brazda
authors.forename: Christian
authors.initials: C
authors.lastname: Voss
authors.forename: Veronica
authors.initials: V
authors.lastname: Estrada
authors.forename: Homaira
authors.initials: H
authors.lastname: Lodin
authors.forename: Nils
authors.initials: N
authors.lastname: Weinrich
authors.forename: Klaus
authors.initials: K
authors.lastname: Seide
authors.forename: Jörg
authors.initials: J
authors.lastname: Müller
authors.forename: Hans W
authors.initials: HW
authors.lastname: Müller
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008962:Models, Theoretical; D009416:Nerve Regeneration / Q000187:drug effects; D019904:Polymethyl Methacrylate / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000166:cytology*; D013119:Spinal Cord Injuries / Q000188:drug therapy* / Q000601:surgery
chemical_list: D019904:Polymethyl Methacrylate
keywords: Neuronal regeneration; Polymethylmethacrylate; Soft tissue biomechanics; Spinal cord injury; Spinal surgery